Engineers at Opel, in collaboration with the Technical University of Darmstadt, are developing eye-tracking technology for application in a third-generation of automotive adaptive lighting that will be introduced after the current AFL+ bi-xenon system. The concept is that the driver’s eye movements will control the direction and intensity of light.
High-performance eye-tracking systems can require 5 to 10 cameras; for the Opel system, the researchers began with a simple webcam. Focused on the driver’s head, it scanned prominent points, such as the nose and eyes, to detect movement and thereby the driver’s line of sight.
The system then translated the information gathered into data commands for electronically-controlled actuators, which quickly aligned the vehicle’s headlamp projectors. While this technique came very close to achieving eye-control of the headlamps, calculation of data still took too long and the recording rate of the webcam was also too slow to meet the demanding requirements of road traffic conditions.
Optimization of the camera’s operating parameters and the adaptation of the eye-tracking algorithm brought a breakthrough. The camera is now equipped with peripheral infra-red sensors and central photo-diodes which together enable it to scan the driver’s eyes more than 50 times per second in dusk and night-time conditions.
|The camera in Opel’s eye-tracking system scans the driver’s eyes more than 50 times per second to instantaneously adjust the headlamp beam. Click to enlarge.|
With much faster data processing and transmission, the headlamp actuators react instantaneously to make both horizontal and vertical adjustments.
However, in practice, a driver’s eyes very naturally and unconsciously jump from one focal point to another. If the headlights were allowed to follow this movement precisely, the vehicle’s light cone would jerk around erratically.
To overcome this problem, we have successfully developed a sophisticated delay algorithm which ensures a suitably flowing movement for the light cone. Another major benefit is that the eye-tracker doesn’t have to be individually calibrated for a particular driver. The system works perfectly with anyone behind the wheel, no matter what their size.—Ingolf Schneider, Director Lighting Technology at Opel
Even if the driver is momentarily distracted from looking at the road ahead, lighting is always provided in the direction of travel because the low beam of the headlamps is programmed to ensure sufficient illumination.
We’ve been pursuing this concept of controlling the direction and intensity of light based on where the driver is looking for around two years. The more we understand the benefits of this technology, the more intensively we push ahead with our joint project.—Ingolf Schneider
AFL+. The current generation AFL+ lighting system from Opel is offered across a wide range of models. In combination with the Opel Eye front camera, it features up to 10 lighting functions, using xenon headlamp beams which automatically adapt to a diverse range of driving situations. For different road and weather conditions, variable light distribution is automatically provided as appropriate for pedestrian areas, city driving, country roads, highways and adverse weather.
AFL+ also includes functions such as dynamic curve light, cornering light and the use of energy-saving LED daytime running lights. The direction and intensity of the light beam is adjusted according to both steering angle and vehicle speed. In addition, high beam light assistant switches the headlamps to low beam whenever the forward-facing Opel Eye camera, integrated in the interior mirror mounting, detects the proximity of headlamps or tail-lights of other vehicles.
A Light and Visibility Pack also includes automatic low beam lighting, together with tunnel recognition. With this array of automatic lighting functions, AFL+ not only improves the visibility of one’s own vehicle but also reduces driver stress and night-time drowsiness.
Parallel to refining the proven AFL+ and conducting the development of the future eye-tracking lighting generation, engineers at Opel’s International Technical Development Center in Rüsselsheim are currently completing the final validation tests on their next-generation lighting system for upcoming Opel vehicles. LED matrix light provides glare-free, high beam lighting, which is automatically and constantly adapted for varying traffic situations.
In this way, the LED matrix light functions with the Opel Eye front camera, but its accuracy and adaptive capacity go one step forward. When light sources are detected from oncoming or preceding traffic, individual LEDs in the relevant zone are deactivated, while the rest of the road remains brightly illuminated. It will be introduced within the next 18 months.